git-annex/RemoteDaemon/Transport/Ssh.hs
Joey Hess c2f612292a
start splitting out readonly values from AnnexState
Values in AnnexRead can be read more efficiently, without MVar overhead.
Only a few things have been moved into there, and the performance
increase so far is not likely to be noticable.

This is groundwork for putting more stuff in there, particularly a value
that indicates if debugging is enabled.

The obvious next step is to change option parsing to not run in the
Annex monad to set values in AnnexState, and instead return a pure value
that gets stored in AnnexRead.
2021-04-02 15:51:44 -04:00

108 lines
3.2 KiB
Haskell

{- git-remote-daemon, git-annex-shell over ssh transport
-
- Copyright 2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module RemoteDaemon.Transport.Ssh (transport, transportUsingCmd) where
import Annex.Common
import Annex.Ssh
import RemoteDaemon.Types
import RemoteDaemon.Common
import Remote.Helper.Ssh
import qualified RemoteDaemon.Transport.Ssh.Types as SshRemote
import Utility.SimpleProtocol
import qualified Git
import Git.Command
import Annex.ChangedRefs
import Control.Concurrent.STM
import Control.Concurrent.Async
transport :: Transport
transport rr@(RemoteRepo r _) url h ichan ochan = do
v <- liftAnnex h $ git_annex_shell ConsumeStdin r "notifychanges" [] []
case v of
Nothing -> noop
Just (cmd, params) -> transportUsingCmd cmd params rr url h ichan ochan
transportUsingCmd :: FilePath -> [CommandParam] -> Transport
transportUsingCmd cmd params rr@(RemoteRepo r gc) url h@(TransportHandle (LocalRepo g) st rd) ichan ochan = do
-- enable ssh connection caching wherever inLocalRepo is called
g' <- liftAnnex h $ sshOptionsTo r gc g
let transporthandle = TransportHandle (LocalRepo g') st rd
transportUsingCmd' cmd params rr url transporthandle ichan ochan
transportUsingCmd' :: FilePath -> [CommandParam] -> Transport
transportUsingCmd' cmd params (RemoteRepo r gc) url transporthandle ichan ochan =
robustConnection 1 $ withCreateProcess p go
where
p = (proc cmd (toCommand params))
{ std_in = CreatePipe
, std_out = CreatePipe
, std_err = CreatePipe
}
go (Just toh) (Just fromh) (Just errh) pid = do
-- Run all threads until one finishes and get the status
-- of the first to finish. Cancel the rest.
status <- catchDefaultIO (Right ConnectionClosed) $
handlestderr errh
`race` handlestdout fromh
`race` handlecontrol
send (DISCONNECTED url)
hClose toh
hClose fromh
void $ waitForProcess pid
return $ either (either id id) id status
go _ _ _ _ = error "internal"
send msg = atomically $ writeTChan ochan msg
fetch = do
send (SYNCING url)
ok <- inLocalRepo transporthandle $
runBool [Param "fetch", Param $ Git.repoDescribe r]
send (DONESYNCING url ok)
handlestdout fromh = do
ml <- getProtocolLine fromh
case parseMessage =<< ml of
Just SshRemote.READY -> do
send (CONNECTED url)
handlestdout fromh
Just (SshRemote.CHANGED (ChangedRefs shas)) -> do
whenM (checkShouldFetch gc transporthandle shas) $
fetch
handlestdout fromh
-- avoid reconnect on protocol error
Nothing -> return ConnectionStopping
handlecontrol = do
msg <- atomically $ readTChan ichan
case msg of
STOP -> return ConnectionStopping
LOSTNET -> return ConnectionStopping
_ -> handlecontrol
-- Old versions of git-annex-shell that do not support
-- the notifychanges command will exit with a not very useful
-- error message. Detect that error, and avoid reconnecting.
-- Propigate all stderr.
handlestderr errh = do
s <- hGetSomeString errh 1024
hPutStr stderr s
hFlush stderr
if "git-annex-shell: git-shell failed" `isInfixOf` s
then do
send $ WARNING url $ unwords
[ "Remote", Git.repoDescribe r
, "needs its git-annex upgraded"
, "to 5.20140405 or newer"
]
return ConnectionStopping
else handlestderr errh